sdbusplus: use shorter type aliases

The sdbusplus headers provide shortened aliases for many types.
Switch to using them to provide better code clarity and shorter
lines.  Possible replacements are for:
  * bus_t
  * exception_t
  * manager_t
  * match_t
  * message_t
  * object_t
  * slot_t

Change-Id: Ib77ec68be0c5ffd73a8dcc140e22f011191c9de5
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/requester/mctp_endpoint_discovery.cpp b/requester/mctp_endpoint_discovery.cpp
index 9440ed0..0d63cb2 100644
--- a/requester/mctp_endpoint_discovery.cpp
+++ b/requester/mctp_endpoint_discovery.cpp
@@ -22,7 +22,7 @@
 namespace pldm
 {
 MctpDiscovery::MctpDiscovery(
-    sdbusplus::bus::bus& bus,
+    sdbusplus::bus_t& bus,
     std::initializer_list<MctpDiscoveryHandlerIntf*> list) :
     bus(bus),
     mctpEndpointAddedSignal(